The present invention relates to a complex diagnostic apparatus, a complex diagnostic system, an ultrasound diagnostic apparatus, an X-ray diagnostic apparatus and a complex diagnostic image-generating method. The present invention more specifically relates to a complex diagnostic apparatus, a complex diagnostic system, an ultrasound diagnostic apparatus, an X-ray diagnostic apparatus and a complex diagnostic image-generating method which perform ultrasound diagnosis using ultrasound images and radiation diagnosis using radiographic images in combination.
Ultrasound diagnostic apparatuses using ultrasound images and radiation diagnostic apparatuses using radiographic images such as X-ray images have conventionally been put to practical use in the medical field.
In general, an ultrasound diagnostic apparatus includes an ultrasound probe having a built-in transducer array and an apparatus body connected to the ultrasound probe. The ultrasound probe transmits ultrasonic waves toward a subject and receives ultrasonic echoes from the subject in its respective channels, and the apparatus body electrically processes the reception signals to generate an ultrasound image.
In a radiation diagnostic apparatus, a radiation source and a radiographic image generator are disposed so as to interpose a subject therebetween. Radiation emitted from the radiation source is detected in the radiographic image generator via the subject and a radiographic image is formed in the radiographic image generator according to the detected radiation dose.
Ultrasound images and radiographic images generated by combining an ultrasound diagnostic apparatus and a radiation diagnostic apparatus with each other have recently been used in diagnosis. For example, mutually different information can be obtained from ultrasound images and radiographic images. More specifically, ultrasound images can clarify muscle, cartilage and other soft tissues in a subject's body, whereas radiographic images can clarify bone and other hard tissues. Therefore, diagnostic accuracy and efficiency can be enhanced by generating an ultrasound image and a radiographic image corresponding to the same section in a subject's body by combining an ultrasound diagnostic apparatus with a radiation diagnostic apparatus.
It is also possible to combine an ultrasound diagnostic apparatus with a radiation diagnostic apparatus so as to obtain a radiographic image including a lesion area by searching for the lesion area generated in a subject's body using an ultrasound image and irradiating the lesion area with radiation. In this process, by generating an X-ray image on a section perpendicular to a specific section in the subject's body corresponding to the ultrasound image, the X-ray image that can be obtained reliably includes the lesion area.
An ultrasound image and an X-ray image are thus required to be generated so as to accurately correspond to each other in orientation of sections in a subject's body according to the diagnosis.
A catheter which is inserted into a blood vessel or the like in a subject's body is known as a diagnostic apparatus making use of both an ultrasound image and a radiographic image. For example, JP 2010-057910 A discloses acquiring a static X-ray image and a real-time ultrasound image upon insertion of a guide wire for guiding a catheter into a subject's body and displaying the movement of the guide wire as detected by the ultrasound image on the X-ray image showing a blood vessel enhanced by contrast medium. The guide wire can be thus smoothly inserted into the blood vessel by tracking the movement of the guide wire using the ultrasound image and the X-ray image.
However, the apparatus for tracking the movement of a guide wire as described in JP 2010-057910 A uses an ultrasound image and an X-ray image to improve the efficiency of the operation for inserting the guide wire into a subject's body, and is not used to make the ultrasound image and the X-ray image accurately correspond to each other.
In order to generate an ultrasound image and an X-ray image which accurately correspond to each other in orientation of sections in a subject's body, the direction of transmission of an ultrasonic beam transmitted from an ultrasound probe is required to be substantially parallel to the direction of radiation emitted from a radiation source. However, the ultrasound probe is used as it is moved in various directions so that the diagnostic site in a subject's body can be clearly displayed, and it is difficult to accurately recognize the direction of ultrasonic beam transmission from the position of the ultrasound probe. Therefore, it is difficult to make an adjustment so that the direction of ultrasonic beam transmission may be parallel to the direction of radiation, and there is a problem that generated ultrasound images and radiographic images cannot accurately correspond to each other.